EMERGENCIES IN MR ENVIRONMENT

EMERGENCIES IN MR ENVIRONMENT

3 categories:

•          Quench
•    Magnetic field emergencies
•           Patient emergencies

QUENCHING:

- Sudden loss of absolute zero of temperature in the magnet coils

- Coils become resistive

- Rapid escape of helium from cryogen bath

- Accidental quenching

        - Manual quenching

- In case of emergency (if a person pinned to a     magnet by a large ferromagnetic object)

- can cause severe, irreparable damage to the superconducting coils

System requirements for quenching:

- Helium venting equipment

- Oxygen monitor

- Alarms when oxygen levels fall below certain level

Steps in case of a quench:

- Do not panic

- Turn on exhaust (if not automatically turned on)

- Open the door between operator room and hallway

- Enter the scan room—undock table—help patient exit

- Evacuate area and return only when oxygen levels are normal.

- IF HELIUM IS VENTING INTO THE ROOM THE SCAN ROOM MAY NOT OPEN…..

In that case:

- Try opening the door several times, but

-- If not opened in 45 seconds

- Break window to scan room to relieve

  Pressure

- Enter the scan room

- Evacuate patient

MAGNETIC FIELD EMERGENCIES:

- If somebody pinned against the magnet or in other   magnetic-field-related emergency

                    QUENCH THE MAGNET

                                      But

        It results in several days’ downtime

                                        So

Do not press QUENCH BUTTON unless true emergency

- Do not test the button, leave to qualified service personnel

PATIENT EMERGENCY:

- Conditions

        - Seizure or claustrophobia

        - Greater potential of cardiac arrest

        - Unconscious, heavily sedated or confused patient

- Monitor these patients closely as usually direct observation of the patient not possible due to partial obscuration by magnet enclosure

- Emergency personnel either remains with the patient or on stand-by alert

Procedure to be followed in case of patient emergency:

- Hit emergency stop button

- Evacuate patient to the emergency medical treatment area outside exclusion zone

- Follow emergency hospital protocol

                                                                        Ravi

                                                               BS(RT)